1. Field of the Invention
The present invention relates to a hinge apparatus for a trunk lid, and more particularly, to a hinge apparatus for a trunk lid, which is configured to compensate for deterioration in opening force for the trunk lid even though the opening force deteriorates due to plastic deformation of a spring.
2. Description of Related Art
As illustrated in FIG. 1, a trunk room of a passenger vehicle is a space at a rear side of the vehicle for accommodating luggage, and a trunk lid 1 is rotatably mounted to a vehicle body, thereby opening and closing the trunk room.
A shape of a trunk lid 1 is variously designed in accordance with the type of vehicle and the shape classification, but a shape of the trunk lid 1 of a general sedan has a bent shape so as to shield an upper side and a rear side of the trunk room, and the trunk lid 1 is coupled to the vehicle body through a hinge apparatus so as to be opened and closed.
The hinge apparatus includes a hinge arm 2 which has one end rotatably coupled to the vehicle body, and the other end connected with the trunk lid 1, and a spring or a lifter which provides elastic force to the hinge arm 2.
The hinge arms 2 are disposed at both sides of the trunk lid 1, respectively, and rotatably mounted to brackets 4 fixed to the vehicle body. Further, a torsion spring or a gas lifter is additionally coupled to the hinge arm 2 so as to allow the trunk lid 1 to pop up to a predetermined height and assist force in lifting up the trunk lid 1 when the trunk lid 1 is opened.
When describing a structure in the related art in which the torsion spring 3 among others is coupled, in a state in which one end of the torsion spring 3 is supported by one side hinge bracket 5 rotatably coupled to the hinge arm 2, the other end of the torsion spring 3 is mounted to the other side hinge bracket 5 in a state in which the other end of the torsion spring 3 may be twisted at a predetermined angle.
That is, the torsion spring 3 is configured to be elastically twisted when the trunk lid 1 is closed, and to lift up the trunk lid 1 using elastic restoring force when the trunk lid 1 is unlocked.
However, there is a problem in that elastic restoring force of the torsion spring 3 deteriorates due to repetitive torsion as time passed, and plastic deformation of the torsion spring 3 occurs.
As an amount of plastic deformation of the torsion spring 3 is increased, elastic restoring force deteriorates, and as a result, a pop-up amount of the trunk lid 1 is decreased. Furthermore, when the pop-up amount is decreased, a sensor cannot sense an opening signal of the trunk lid 1, and a result, an indicating lamp for indicating an opened state of the trunk lid 1 is likely to be erroneously operated on an instrument panel.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.